Arthroscopic devices and methods

ABSTRACT

A resecting probe includes a shaft assembly having an outer sleeve and an inner sleeve. The outer sleeve has an axial bore and an outer window in a distal side thereof, and the inner sleeve has an axial extraction channel and inner window in a distal side thereof. The inner sleeve is rotationally disposed in the axial bore of the outer sleeve to allow the inner sleeve window to be rotated in and out of alignment with the outer sleeve window, and the shaft assembly forms a flow aperture in a distal portion when the inner cutting window and the outer cutting window are out of alignment. An electrode is carried on the inner sleeve, and a motor drive is coupled to rotate the inner sleeve relative to the outer sleeve. A controller is coupled to the motor drive and controls rotation of the inner sleeve and can stop rotation of the inner sleeve in a stop position where the outer and inner windows are out of alignment, providing the flow aperture to allow cooling of fluid in a working space and cooling of the probe handpiece during use.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of provisional applications62/551,150 (Attorney Docket No. 41879-736.101), filed Aug. 28, 2017, and62/696,762 (Attorney Docket No. 41879-745.101), filed Jul. 11, 2018, thefull disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention relates to a medical system that includes variations ofmotor-driven arthroscopic shavers that carry RF electrodes for ablatingof coagulating tissue.

In endoscopic and other surgical procedures including subacromialdecompression, anterior cruciate ligament reconstruction involvingnotchplasty, and arthroscopic resection of the acromioclavicular joint,there is a need for cutting and removal of bone and soft tissue.Currently, surgeons use arthroscopic shavers and burrs having rotationalcutting surfaces to remove hard tissue in such procedures.

To promote efficiency, endoscopic tool systems including, a reusablehand piece and a selection of interchangeable tool probes have differentworking ends have been proposed. Such working ends may each have two ormore functionalities, such as soft tissue removal and hard tissueresection, so such tools systems can provide dozens of specificfunctionalities, providing great flexibility.

For example, such endoscopic tool systems may have tool probes whichcombine a rotatable cutter and a radiofrequency electrode suitable forablation and/or coagulation. When operating in a cutting mode, anegative pressure is typically applied to the probe to draw tissue intoa cutting window and thereafter suction tissue chips out through anextraction channel. When operating in an electrosurgical mode, incontrast, there typically would be no negative pressure applied and nofluid flow through the probe.

While the combination tool of the invention with both a rotatable cutterand an RF electrode provides a significant advantage, in some suchdesigns, there is a need to cool the probe and/or hand piece whenoperating in the electrosurgical mode.

It is therefore an object of the present invention to provide improvedsurgical systems and methods for their use, such as improvedarthroscopic tissue cutting and removal systems of the type whichcombine a rotatable mechanical cutter and a radiofrequency electrodesuitable for ablation and/or coagulation. In particular, it would beadvantageous to provide such a tissue cutting and removal system with arotatable cutter and a radiofrequency electrode having an improvedcooling function when operating in the electrosurgical mode. At leastsome of these objectives will be met by the inventions described herein.

2. Description of the Background Art

Relevant commonly owned patents and applications include U.S. Pat. Nos.6,821,275; 8,333,763; 9,855,675; 9,681,913; and copending applicationSer. Nos. 15/454,690; 15/483,940; 15/495,620; 15/633,372; 15/659,241;15/271,187; 15/855,684; 15/920,130; 15/920,258; 15/974,565, the fulldisclosures of which are incorporated herein by reference.

SUMMARY OF THE INVENTION

The present invention provides improved apparatus and methods forresecting and otherwise treating tissue. Such apparatus and methodsprovide endoscopic tools for both mechanical resection andelectrosurgical treatment, such as ablation and coagulation. Theendosurgical tools also referred to as probes and resecting probes, willtypically but not necessarily comprise a reusable handle and a removableor detachable probe shaft, where the probe shaft includes both a cuttingfunction and an electrosurgical function. The probe shaft will beconfigured to allow for fluid aspiration during both cutting andelectrosurgical operation, where the fluid flow provides cooling duringthe electrosurgical operation.

In a first aspect, the present invention provides a resecting probecomprising a shaft assembly and a motor drive. The shaft assemblyincludes (i) an outer sleeve having an axial bore and an outer window ina distal side thereof and (ii) an inner sleeve having an axialextraction channel configured to connect to a negative pressure source(typically for aspiration of tissue chips or debris as described furtherbelow) and an inner window in a distal side thereof. The inner sleeve isrotationally disposed in the axial bore of the outer sleeve which allowsthe inner sleeve window to rotate relative to the outer sleeve window tothereby cut tissue. The inner sleeve is typically motor-driven to cuttissue that is drawn into the windows and aspiration is applied to drawfluid and tissue debris through the extraction channel. The shaftassembly is further configured to form a flow aperture in a distalportion thereof when the inner cutting window and the outer cuttingwindow are out of alignment, allowing a cooling fluid flow through theshaft assembled (and optionally a handpiece as described hereinafter)during electrosurgical use when the cutting windows are not aligned,blocking the tissue debris aspiration flow path. An electrode is carriedon the inner sleeve, and the motor drive is coupled to rotate the innersleeve relative to the outer sleeve.

The flow aperture can be formed in a variety of ways. For example, anouter sleeve aperture may be formed in a wall of the outer sleeve,wherein such outer sleeve aperture aligns with the inner window when theinner sleeve is in a stop position. Typically, the outer sleeve aperturecomprises a plurality of slots formed in the wall of the outer sleeve,and fluid may flow into the extraction channel to provide a coolingfunction while tissue and other debris is blocked by the configurationof the slots. Alternatively, such apertures or slots may be formed in awall of the inner sleeve, wherein such inner sleeve apertures align withthe outer window when the inner sleeve is in the stop position. Theinner sleeve apertures typically comprise a plurality of slots formed inthe wall of the inner sleeve to serve a function similar to thatdescribed previously.

In preferred embodiments, a controller is coupled to the motor drive andconfigured to control rotation of the inner sleeve and to stop rotationof the inner sleeve in a stop position where the outer and inner windowsare out of alignment, alternately called a window-closed position. Thecontroller will typically be further configured to deliver energy to theelectrode when the inner sleeve is in the stop position. The resectingprobe will usually further comprise an aspiration source coupled to theextraction channel in the inner sleeve to draw tissue through the outerand inner windows when said windows are at least partially rotationallyaligned, and the controller will often be further configured to operatein a first mode wherein both (i) the aspiration source draws fluid andtissue into said windows when at least partially aligned, and (ii) themotor drive rotates the inner sleeve to resect tissue. The controllermay be further configured to operate in a second mode wherein (i) theaspiration source draws fluid through the flow aperture and inner windowin said stop position, and (ii) the electrode is activated to applyenergy to tissue.

Exemplary structural and operating parameters include adjusting theaspiration source to draw fluid through the flow-restricted aperture ata rate of at least 25 ml/min to enhance cooling of the probe and coolingof fluid in the working space. The flow apertures usually havedimensions selected to inhibit tissue from being aspirated therethrough,i.e., the apertures may act as a filter, typically comprising one ormore elongated slots. The elongated slot typically has a width rangingfrom 0.005″ to 0.10″.

In other specific aspects of the resecting probe, the inner window isformed within a ceramic portion of the inner sleeve and the electrode iscarried by a ceramic portion of the inner sleeve. A ceramic cutting tipmay be carried at a distal end in the inner sleeve, and the electrodemay be carried on a side of the ceramic cutting tip. In some instances,the ceramic cutting tip is fluted and the electrode is disposed betweenadjacent flutes.

In a second aspect, the present invention provides methods for treatingtissue in a fluid-filled working space. Such methods comprise providinga probe including (i) an outer sleeve having an axial bore and an outerwindow in a distal side thereof and (ii) an inner sleeve configured torotate in the axial bore of the outer sleeve and having an axialextraction channel and an inner window in a distal side thereof. Theinner window is rotated in and out of alignment with the outer window asthe inner sleeve rotates, and the sleeves are configured to form flowapertures in a distal portion thereof when the inner cutting window andthe outer cutting window are out of alignment. A distal end of the probeis urged against a target tissue, and a negative pressure is appliedthrough the extraction channel. The inner sleeve is rotated to resecttissue which is drawn through the outer window and the inner window whenthe windows are aligned as they rotate. The inner sleeve may be stoppedin a stop position in which said outer and inner windows are notrotationally aligned, and an electrode carried by the inner sleeve maybe activated, typically by applying radiofrequency (RF) current to treattissue while actuating the aspiration source to draws fluid through theflow apertures to thereby cool the probe and fluid in the working space.

In particular examples, operating in a first mode comprise (i)controlling a motor drive to rotate the inner sleeve, and (ii) actuatingan aspiration source to apply a negative pressure through the extractionchannel. Typically, such a first mode includes operating the aspirationsource to draw fluid through the windows at a rate of at least 25ml/min. A second operating mode may comprise (i) stopping the innersleeve in the stop position, (ii) actuating the aspiration source, and(iii) activating the electrode. In specific examples, operating theaspiration source draws fluid through the flow aperture at a rate of atleast 25 ml/min.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention will now be discussed withreference to the appended drawings. It should be appreciated that thedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting in scope.

FIG. 1 is a perspective view of an arthroscopic cutting system thatincludes reusable hand piece with a motor drive and a detachablesingle-use cutting probe, wherein the cutting probe is shown in twoorientations as it may be coupled to the hand piece with the probe andworking end in upward orientation or a downward orientation relative tothe hand piece, and wherein the hand piece includes an LCD screen fordisplaying operating parameters of system during use together withcontrol actuators on the hand piece.

FIG. 2A is an enlarged longitudinal sectional view of the hub of theprobe of FIG. 1 taken along line 2A-2A of FIG. 1 with the hub and probein an upward orientation relative to the hand piece, further showingHall effect sensors carried by the hand piece and a plurality of magnetscarried by the probe hub for device identification, for probeorientation and determining the position of motor driven components ofthe probe relative to the hand piece.

FIG. 2B is a sectional view of the hub of FIG. 1 taken along line 2B-2Bof FIG. 1 with the hub and probe in a downward orientation relative tothe hand piece showing the Hall effect sensor and magnets having adifferent orientation compared to that of FIG. 2A.

FIG. 3A is an enlarged perspective view of the working end of the probeof FIG. 1 in an upward orientation with the rotatable cutting member ina first position relative to the outer sleeve wherein the window in thecutting member is aligned with the window of the outer sleeve.

FIG. 3B is a perspective view of the working end of FIG. 1 in an upwardorientation with the rotatable cutting member in a second positionrelative to the outer sleeve wherein the electrode carried by thecutting member is aligned with a centerline of the window of the outersleeve.

FIG. 4 is a perspective view of a working end of a variation of a probethat may be detachably coupled to the hand piece of FIG. 1, wherein theworking end includes a bone burr extending distally from the outersleeve.

FIG. 5 is a perspective view of a working end of a variation of a probethat may be detachably coupled to the hand piece of FIG. 1, wherein theworking end has a reciprocating electrode.

FIG. 6 is a perspective view of a working end of another variation of aprobe that may be detachably coupled to the hand piece of FIG. 1,wherein the working end has a hook electrode that has extended andnon-extended positions.

FIG. 7 is a perspective view of a working end of yet another variationof a probe that may be detachably coupled to the hand piece of FIG. 1,wherein the working end has an openable-closeable jaw structure forcutting tissue.

FIG. 8 is a chart relating to set speeds for a probe with a rotatingcutting member as in FIGS. 1 and 3A that schematically shows the methodused by a controller algorithm for stopping rotation of the cuttingmember in a selected default position.

FIG. 9A is a longitudinal sectional view of a probe hub that is similarto that of FIG. 2A, except the hub of FIG. 9A has an internal cammechanism for converting rotational motion to linear motion to axiallyreciprocate an electrode as in the working end of FIG. 5, wherein FIG.9A illustrated the magnets in the hub and drive coupling are the same asin FIG. 2A and the hub is in an upward facing position relative to thehand piece.

FIG. 9B is a sectional view of the hub of FIG. 9A rotated 180° in adownward facing position relative to the hand piece.

FIG. 10A is a perspective view of a working end of another variation ofa probe that shows a motor-driven, rotating ceramic cutter carrying anelectrode, with the cutter in a stopped position with the electrodealigned with the centerline of the window in the outer sleeve.

FIG. 10B is another view of the working end of FIG. 10A rotated 180° toshow fluid outflow apertures in the outer sleeve

FIG. 11 is a sectional view of the working end of FIGS. 10A-109B takenalong line 11-11 of FIG. 10B showing fluid outflows.

FIG. 12A is a perspective view of a working end of another variation ofa probe that shows a motor-driven, rotating ceramic cutter carrying anelectrode.

FIG. 12B is another view of the working end of FIG. 12A with the ceramiccutter rotated 180° to show fluid outflow apertures in the ceramiccutter.

FIG. 13 is a perspective view of a working end of another variation of aprobe that shows a motor-driven, rotating ceramic cutter carrying anelectrode, wherein the electrode has a radial edge extending radiallyoutward that is adapted for engaging tissue while being rotated andenergized.

FIG. 14 is a perspective view of a another variation of a working end ofa single-use probe similar to that of FIGS. 3A-3B with an inner sleeveand ceramic cutting member that carries an active RF electrode thatrotates in an outer sleeve, wherein the outer sleeve can be metal orceramic.

FIG. 15A is view of the working end of the inner sleeve and ceramiccutting member removed from the outer sleeve in a first rotationalorientation.

FIG. 15B is view of the inner sleeve and ceramic cutting member of FIG.15A in a second rotational orientation that is rotated 180° from theview of FIG. 15A.

FIG. 16 is view of the outer sleeve of FIG. 14 separated from the innersleeve to show the side or cooling apertures.

FIG. 17 is view of another outer sleeve similar to that of FIG. 14 withdifferently shaped side or cooling apertures.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to bone cutting and tissue removal devicesand related methods of use. Several variations of the invention will nowbe described to provide an overall understanding of the principles ofthe form, function and methods of use of the devices disclosed herein.In general, the present disclosure provides for variations ofarthroscopic tools adapted for cutting bone, soft tissue, meniscaltissue, and for RF ablation and coagulation. The arthroscopic tools aretypically disposable and are configured for detachable coupling to anon-disposable hand piece that carries a motor drive component. Thisdescription of the general principles of this invention is not meant tolimit the inventive concepts in the appended claims.

In one variation shown in FIG. 1, the arthroscopic system 100 of thepresent invention provides a hand piece 104 with motor drive 105 and adisposable shaver assembly or probe 110 with a proximal hub 120 that canbe received by receiver or bore 122 in the hand piece 104. In oneaspect, the probe 110 has a working end 112 that carries a high-speedrotating cutter that is configured for use in many arthroscopic surgicalapplications, including but not limited to treating bone in shoulders,knees, hips, wrists, ankles and the spine.

In FIGS. 1, 2A and 3A, it can be seen that probe 110 has a shaft 125extending along longitudinal axis 128 that comprises an outer sleeve 140and an inner sleeve 142 rotatably disposed therein with the inner sleeve142 carrying a distal ceramic cutting member 145 (FIG. 3A). The shaft125 extends from the proximal hub 120 wherein the outer sleeve 140 iscoupled in a fixed manner to the hub 120 which can be an injectionmolded plastic, for example, with the outer sleeve 140 insert moldedtherein. The inner sleeve 142 is coupled drive coupling 150 that isconfigured for coupling to the rotating motor shaft 151 of motor driveunit 105. More in particular, the rotatable cutting member 145 that isfabricated of a ceramic material with sharp cutting edges on opposingsides 152 a and 152 b of window 154 therein for cutting soft tissue. Themotor drive 105 is operatively coupled to the ceramic cutter to rotatethe cutting member at speeds ranging from 1,000 rpm to 20,000 rpm. InFIG. 3B, it can be seen that cutting member 145 also carries an RFelectrode 155 in a surface opposing the window 154. The cutting member145 rotates and shears tissue in the toothed opening or window 158 inthe outer sleeve 140 (FIG. 3A). A probe of the type shown in FIG. 1 isdescribed in more detail in co-pending and commonly owned patentapplication Ser. No. 15/421,264 filed Jan. 31, 2017 (Atty. Docket41879-714.201) titled ARTHROSCOPIC DEVICES AND METHODS which isincorporated herein in its entirety by this reference.

As can be seen in FIG. 1, the probe 110 is shown in two orientations fordetachable coupling to the hand piece 104. More particularly, the hub120 can be coupled to the hand piece 104 in an upward orientationindicated at UP and a downward orientation indicated at DN where theorientations are 180° opposed from one another. It can be understoodthat the upward and downward orientations are necessary to orient theworking end 112 either upward or downward relative to the hand piece 104to allow the physician to interface the cutting member 145 with targetedtissue in all directions without having to manipulate the hand piece in360° to access tissue.

In FIG. 1, it can be seen that the handle 104 is operatively coupled byelectrical cable 160 to a controller 165 which controls the motor driveunit 105 Actuator buttons 166 a, 166 b or 166 c on the handle 104 can beused to select operating modes, such as various rotational modes for theceramic cutting member 145. In one variation, a joystick 168 can bemoved forward and backward to adjust the rotational speed of the ceramiccutting member 145. The rotational speed of the cutter can continuouslyadjustable, or can be adjusted in increments up to 20,000 rpm. An LCDscreen 170 is provided in the hand piece for displaying operatingparameters, such as cutting member RPM, mode of operation, etc.

It can be understood from FIG. 1 that the system 100 and hand piece 104is adapted for use with various disposable probes which can be designedfor various different functions and procedures For example, FIG. 4illustrates a different variation of a probe working end 200A that issimilar to working end 112 of probe 110 of FIGS. 3A-3B, except theceramic cutting member 205 extends distally from the outer sleeve 206and the cutting member has burr edges 208 for cutting bone. The probe ofFIG. 4 is described in more detail in co-pending and commonly ownedpatent application Ser. No. 15/271,184 filed Sep. 20, 2016 (Atty. Docket41879-728.201) titled ARTHROSCOPIC DEVICES AND METHODS. FIG. 5illustrates a different variation of a probe working end 200B with areciprocating electrode 210 in a type of probe described in more detailin co-pending and commonly owned patent application Ser. No. 15/410,723filed Jan. 19, 2017 (Atty. Docket 41879-713.201) titled ARTHROSCOPICDEVICES AND METHODS. In another example, FIG. 6 illustrates anothervariation of a probe working end 200C that has an extendable-retractablehook electrode 212 in a probe type described in more detail inco-pending and commonly owned patent application Ser. No. 15/454,342filed Mar. 9, 2017 (Atty. Docket 41879-715.201) titled ARTHROSCOPICDEVICES AND METHODS. In yet another example, FIG. 7 illustrates avariation of a working end 200D in a probe type having anopenable-closable jaw structure 215 actuated by reciprocating member 218for trimming meniscal tissue or other tissue as described in more detailin co-pending and commonly owned patent application Ser. No. 15/483,940filed Apr. 10, 2017 (Atty. Docket 41879-721.201) titled ARTHROSCOPICDEVICES AND METHODS. All of the probes of FIGS. 4-7 can have a hubsimilar to hub 120 of probe 110 of FIG. 1 for coupling to the same handpiece 104 of FIG. 1, with some of the probes (see FIGS. 5-7) having ahub mechanism for converting rotational motion to linear motion. All ofthe patent applications just identified in this paragraph areincorporated herein by this reference.

FIG. 1 further shows that the system 100 also includes a negativepressure source 220 coupled to aspiration tubing 222 which communicateswith a flow channel 224 in hand piece 104 and can cooperate with any ofthe probes 110, 200A, 200B or 200C of FIGS. 1-3B, 4, 5 and 6. In FIG. 1it also can be seen that the system 100 includes an RF source 225 whichcan be connected to an electrode arrangement in any of the probes 110,200A, 200B or 200C of FIGS. 1-3B, 4, 5 and 6. The controller 165 andmicroprocessor therein together with control algorithms are provided tooperate and control all functionality, which includes controlling themotor drive 105 to move a motor-driven component of any probe workingend 110, 200A, 200B or 200C, as well as for controlling the RF source225 and the negative pressure source 220 which can aspirate fluid andtissue debris to collection reservoir 230.

As can be understood from the above description of the system 100 andhand piece 104, the controller 165 and controller algorithms need to beconfigured to perform and automate many tasks to provide for systemfunctionality. In a first aspect, controller algorithms are needed fordevice identification so that when any of the different probes types110, 200A, 200B, 200C or 200D of FIGS. 1 and 4-7 are coupled to handpiece 104, the controller 165 will recognize the probe type and thenselect algorithms for operating the motor drive 105, RF source 225 andnegative pressure source 220 as is needed for the particular probe. In asecond aspect, the controller is configured with algorithms thatidentify whether the probe is coupled to the hand piece 104 in an upwardor downward orientation relative to the hand piece, wherein eachorientation requires a different subset of the operating algorithms. Inanother aspect, the controller has separate control algorithms for eachprobe type wherein some probes have a rotatable cutter while others havea reciprocating electrode or jaw structure. In another aspect, most ifnot all the probes 110, 200A, 200B, 200C and 200D (FIGS. 1, 4-7) requirea default “stop” position in which the motor-driven component is stoppedin a particular orientation within the working end. For example, arotatable cutter 145 with an electrode 155 needs to have the electrodecentered within an outer sleeve window 158 in a default position such asdepicted in FIG. 3B. Some of these systems, algorithms and methods ofuse are described next.

Referring to FIGS. 1 and 2A-2B, it can be seen that hand piece 104carries a first Hall effect sensor 240 in a distal region of the handpiece 104 adjacent the receiving passageway 122 that receives the hub120 of probe 110. FIG. 2A corresponds to the probe 110 and working end112 in FIG. 1 being in the upward orientation indicated at UP. FIG. 2Bcorresponds to probe 110 and working end 112 in FIG. 1 being in thedownward orientation indicated at DN. The hand piece 104 carries asecond Hall effect sensor 245 adjacent the rotatable drive coupling 150of the probe 110. The probe 110 carries a plurality of magnets as willbe described below that interact with the Hall effect sensors 240, 245to provide multiple control functions in cooperation with controlleralgorithms, including (i) identification of the type of probe coupled tothe hand piece, (ii) the upward or downward orientation of the probe hub120 relative to the hand piece 104, and (iii) the rotational positionand speed of rotating drive collar 150 from which a position of eitherrotating or reciprocating motor-driven components can be determined.

The sectional views of FIGS. 2A-2B show that hub 120 of probe 110carries first and second magnets 250 a and 250 b in a surface portionthereof. The Hall sensor 240 in hand piece 104 is in axial alignmentwith either magnet 250 a or 250 b when the probe hub 120 is coupled tohand piece 104 in an upward orientation (FIGS. 1 and 2A) or a downwardorientation (FIGS. 1 and 2B). In one aspect as outlined above, thecombination of the magnets 250 a and 250 b and the Hall sensor 240 canbe used to identify the probe type. For example, a product portfolio mayhave from 2 to 10 or more types of probes, such as depicted in FIGS. 1and 4-7, and each such probe type can carry magnets 250 a, 250 b havinga specific, different magnetic field strength. Then, the Hall sensor 240and controller algorithms can be adapted to read the magnetic fieldstrength of the particular magnet(s) in the probe which can be comparedto a library of field strengths that correspond to particular probetypes. Then, a Hall identification signal can be generated or otherwiseprovided to the controller 165 to select the controller algorithms foroperating the identified probe, which can include parameters foroperating the motor drive 105, negative pressure source 220 and/or RFsource 225 as may be required for the probe type. As can be seen inFIGS. 1, 2A and 2B, the probe hub 120 can be coupled to hand piece 104in upward and downward orientations, in which the North (N) and South(S) poles of the magnets 250 a, 250 b are reversed relative to the probeaxis 128. Therefore, the Hall sensor 240 and associated algorithms lookfor magnetic field strength regardless of polarity to identify the probetype.

Referring now to FIGS. 1, 2A-2B and 3A-3B, the first and second magnets250 a and 250 b with their different orientations of North (N) and South(S) poles relative to central longitudinal axis 128 of hub 120 are alsoused to identify the upward orientation UP or the downward orientationDN of hub 120 and working end 112. In use, as described above, thephysician may couple the probe 110 to the hand piece receivingpassageway 122 with the working end 112 facing upward or downward basedon his or her preference and the targeted tissue. It can be understoodthat controller algorithms adapted to stop rotation of the cuttingmember 145 in the window 158 of the outer sleeve 104 of working end 112need to “learn” whether the working end is facing upward or downward,because the orientation or the rotating cutting member 145 relative tothe handpiece and Hall sensor 240 would vary by 180°. The Hall sensor240 together with a controller algorithm can determine the orientationUP or the downward orientation DN by sensing whether the North (N) orSouth (S) pole of either magnet 250 a or 250 b is facing upwardly and isproximate the Hall sensor 240.

In another aspect of the invention, in probe 110 (FIG. 1) and otherprobes, the motor-driven component of a working end, such as rotatingcutter 145 of working end 112 of FIGS. 1 and 3A-3B needs to stopped in aselected rotational position relative to a cut-out opening or window 158in the outer sleeve 140. Other probe types may have a reciprocatingmember or a jaw structure as described above, which also needs acontroller algorithm to stop movement of a moving component in aselected position, such as the axial-moving electrodes of FIGS. 5-6 andthe jaw structure of FIG. 7. In all probes, the motor drive 105 couplesto the rotating drive coupling 150, thus sensing the rotational positionof the drive coupling 150 can be used to determine the orientation ofthe motor-driven component in the working end. More in particular,referring to FIGS. 1 and 2A-2B, the drive coupling 150 carries third andfourth magnets 255 a or 255 b with the North (N) and South (S) poles ofmagnets 255 a or 255 b being reversed relative to the probe axis 128.Thus, Hall sensor 245 can sense when each magnet rotates passes the Hallsensor and thereby determine the exact rotational position of the drivecoupling 150 twice on each rotation thereof (once for each magnet 255 a,255 b). Thereafter, a controller tachometer algorithm using a clock candetermine and optionally display the RPM of the drive coupling 150 and,for example, the cutting member 145 of FIG. 3A.

In another aspect of the invention, the Hall sensor 245 and magnets 255a and 255 b (FIGS. 1 and 2A) are used in a set of controller algorithmsto stop the rotation of a motor-driven component of a working end, forexample, cutting member 145 of FIGS. 1 and 3A-3B in a pre-selectedrotational position. In FIG. 3A, it can be seen that the inner sleeve142 and a “first side” of cutting member 145 and window 154 therein isstopped and positioned in the center of window 158 of outer sleeve 140.The stationary position of cutting member 145 and window 154 in FIG. 3Amay be used for irrigation or flushing of a working space to allow formaximum fluid outflow through the probe.

FIG. 3B depicts inner sleeve 142 and a “second side” of cutting member145 positioned about the centerline of window 158 in the outer sleeve140. The stationary or stopped position of cutting member 145 in FIG. 3Bis needed for using the RF electrode 155 to ablate or coagulate tissue.It is important that the electrode 155 is maintained along thecenterline of the outer sleeve window 158 since the outer sleeve 140typically comprises return electrode 260. The position of electrode 155in FIG. 3B is termed herein a “centerline default position”. If thecutting member 145 and electrode 155 were rotated so as to be close toan edge 262 a or 262 b of window 158 in outer sleeve 140, RF currentcould arc between the electrodes 155 and 260 and potentially cause ashort circuit disabling the probe. Therefore, a robust and reliable stopmechanism is required which is described next.

As can be understood from FIGS. 1 and 2A-2B, the controller 165 canalways determine in real time the rotational position of drive coupling150 and therefore the angular or rotational position of the ceramiccutting member 145 and electrode 155 can be determined. A controlleralgorithm can further calculate the rotational angle of the electrode155 away from the centerline default position as the Hall sensor 245 cansense lessening of magnetic field strength as a magnet 255 a or 255 b inthe drive coupling 150 rotates the electrode 155 away from thecenterline default position. Each magnet has a specified, known strengthand the algorithm can use a look-up table with that lists fieldsstrengths corresponding to degrees of rotation away from the defaultposition. Thus, if the Hall signal responsive to the rotated position ofmagnet 255 a or 255 b drops a specified amount from a known peak valuein the centerline default position, it means the electrode 155 has movedaway from the center of the window 158. In one variation, if theelectrode 155 moves a selected rotational angle away from the centerlineposition during RF energy delivery to the electrode, the algorithm turnsoff RF current instantly and alerts the physician by an aural and/orvisual signal, such as an alert on the LCD screen 170 on hand piece 104and/or on a screen on a controller console (not shown). The terminationof RF current delivery thus prevents the potential of an electrical arcbetween electrode 155 and the outer sleeve electrode 260.

It can be understood that during use, when the electrode 155 is in theposition shown in FIG. 3B, the physician may be moving the energizedelectrode over tissue to ablate or coagulate tissue. During such use,the cutting member 145 and electrode 155 can engage or catch on tissuewhich inadvertently rotate the electrode 155 out of the defaultcenterline position. Therefore, the system provides a controlleralgorithm, herein called an “active electrode monitoring” algorithm,wherein the controller continuously monitors position signals generatedby Hall sensor 245 during RF energy delivery in both an ablation modeand a coagulation mode to determine if the electrode 155 and innersleeve 142 have been bumped off the centerline position. In a variation,the controller algorithms can be configured to then re-activate themotor drive 105 to move the inner sleeve 142 and electrode 155 back tothe default centerline position sleeve if electrode 155 had been bumpedoff the centerline position. In another variation, the controlleralgorithms can be configured to again automatically deliver RF currentto RF electrode 155 when it is moved back to the to the defaultcenterline position. Alternatively, the controller 165 can require thephysician to manually re-start the delivery of RF current to the RFelectrode 155 when it is moved back to the to the centerline position.In an aspect of the invention, the drive coupling 150 and thus magnets255 a and 255 b are attached to inner sleeve 142 and cutting member 145in a pre-determined angular relationship relative to longitudinal axis128 so that the Hall sensor generates signals responsive to magnets 255a, 255 b is the same for all probes within a probe type to thus allowthe controller algorithm to function properly.

Now turning to the stop mechanism or algorithms for stopping movement ofa motor-driven component of working end 112, FIG. 8 schematicallyillustrates the algorithm and steps of the stop mechanism. In onevariation, referring to FIG. 8, the stop mechanism corresponding to theinvention uses (i) a dynamic braking method and algorithm to stop therotation of the inner sleeve 142 and cutting member 145 (FIGS. 1, 3A-3B)in an initial position, and thereafter (ii) a secondary checkingalgorithm is used to check the initial stop position that was attainedwith the dynamic braking algorithm, and if necessary, the stop algorithmcan re-activate the motor drive 105 to slightly reverse (or moveforward) the rotation of drive coupling 150 and inner sleeve 142 asneeded to position the cutting member 145 and electrode 155 within atthe centerline position or within 0° to 5° of the targeted centerlinedefault position. Dynamic braking is described further below. FIG. 8schematically illustrates various aspects of controller algorithms forcontrolling the rotational speed of the cutting member and for stoppingthe cutting member 145 in the default centerline position.

In FIG. 8, it can be understood that the controller 165 is operating theprobe 110 of FIGS. 1 and 3A-3B at a “set speed” which may be a PIDcontrolled, continuous rotation mode in one direction or may be anoscillating mode where the motor drive 105 rotates the cutting member145 in one direction and then reverses rotation as is known in the art.At higher rotational speeds such as 1,000 RPM to 20,000 RPM, it is notpractical or feasible to acquire a signal from Hall sensor 245 thatindicates the position of a magnet 255 a or 255 b in the drive coupling150 to apply a stop algorithm. In FIG. 8, when the physician stopcutting with probe 110 by releasing actuation of an actuator button orfoot pedal, current to the motor drive 105 is turned off. Thereafter,the controller algorithm uses the Hall sensor 245 to monitordeceleration of rotation of the drive coupling 150 and inner sleeve 142until a slower RPM is reached. The deceleration period may be from 10 msto 1 sec and typically is about 100 ms. When a suitable slower RPM isreached which is called a “search speed” herein (see FIG. 8), thecontroller 165 re-activates the motor drive 105 to rotate the drivecoupling at a low speed ranging from 10 RPM to 1,000 RPM and in onevariation is between 50 RPM and 250 RPM. An initial “search delay”period ranging from 50 ms to 500 ms is provided to allow the PIDcontroller to stabilize the RPM at the selected search speed.Thereafter, the controller algorithm monitors the Hall position signalof magnet strength and when the magnet parameter reaches a predeterminedthreshold, for example, when the rotational position of drive coupling150 and electrode 155 correspond to the centerline default position ofFIG. 3B, the control algorithm then applies dynamic braking to instantlystop rotation of the motor drive shaft 151, drive coupling 150 and themotor-driven component of the probe. FIG. 8 further illustrates that thecontroller can check the magnet/drive coupling 150 position after thebraking and stopping steps. If the Hall position signal indicates thatthe motor-driven component is out of the targeted default position, themotor drive 105 can be re-activated to move the motor-driven componentand thereafter the brake can be applied again as described above.

Dynamic braking as shown schematically in FIG. 8 may typically stop therotation of the drive coupling 150 with a variance of up to about 0°-15°of the targeted stop position, but this can vary even further whendifferent types of tissue are being cut and impeding rotation of thecutting member 145, and also depending on whether the physician hascompletely disengaged the cutting member from the tissue interface whenthe motor drive is de-activated. Therefore, dynamic braking alone maynot assure that the default or stop position is within a desiredvariance.

As background, the concept of dynamic braking is described in thefollowing literature:https://www.ab.com/support/abdrives/documentation/techpapers/RegenOverview01.pdfandhttp://literature.rockwellautomation.com/idc/groups/literature/documents/wp/drives-wp004_-en-p/pdf.Basically, a dynamic braking system provides a chopper transistor on theDC bus of the AC PWM drive that feeds a power resistor that transformsthe regenerative electrical energy into heat energy. The heat energy isdissipated into the local environment. This process is generally calleddynamic braking with the chopper transistor and related control andcomponents called the chopper module and the power resistor called thedynamic brake resistor. The entire assembly of chopper module withdynamic brake resistor is sometimes referred to as the dynamic brakemodule. The dynamic brake resistor allows any magnetic energy stored inthe parasitic inductance of that circuit to be safely dissipated duringthe turn off of the chopper transistor.

The method is called dynamic braking because the amount of brakingtorque that can be applied is dynamically changing as the loaddecelerates. In other words, the braking energy is a function of thekinetic energy in the spinning mass and as it declines, so does thebraking capacity. So the faster it is spinning or the more inertia ithas, the harder you can apply the brakes to it, but as it slows, you runinto the law of diminishing returns and at some point, there is nolonger any braking power left.

In another aspect of the invention, a method has been developed toincrease the accuracy of the stopping mechanism which is a component ofthe positioning algorithm described above. It has been found that eachmagnet in a single-use probe may vary slightly from its specifiedstrength. As described above, the positioning algorithm uses the Halleffect sensor 245 to continuously monitor the field strength of magnets255 a and 255 b as the drive coupling 150 rotates and the algorithmdetermines the rotational position of the magnets and drive couplingbased on the field strength, with the field strength rising and fallingas a magnet rotates past the Hall sensor. Thus, it is important for thealgorithm to have a library of fields strengths that accuratelycorrespond to degrees of rotation away from a peak Hall signal when amagnet is adjacent the sensor 245. For this reason, an initial step ofthe positioning algorithm includes a “learning” step that allow thecontroller to learn the actual field strength of the magnets 255 a and255 b which may vary from the specified strength. After a new single-useprobe 110 (FIG. 1) is coupled to the hand piece 104, and after actuationof the motor drive 105, the positioning algorithm will rotate the drivecoupling at least 180° and more often at least 360° while the Hallsensor 245 quantifies the field strength of the particular probe'smagnets 255 a and 255 b. The positioning algorithm then stores themaximum and minimum Hall signals (corresponding to North and Southpoles) and calibrates the library of field strengths that correspond tovarious degrees of rotation away from a Hall min-max signal positionwhen a magnet is adjacent the Hall sensor.

In general, a method of use relating to the learning algorithm comprisesproviding a hand piece with a motor drive, a controller, and a probewith a proximal hub configured for detachable coupling to the handpiece, wherein the motor drive is configured to couple to a rotatingdrive coupling in the hub and wherein the drive coupling carries firstand second magnets with North and South poles positioned differentlyrelative to said axis, and coupling the hub to the hand piece,activating the motor drive to thereby rotate the drive coupling andmagnets at least 180°, using a hand piece sensor to sense the strengthof each magnet, and using the sensed strength of the magnets forcalibration in a positioning algorithm that is responsive to the sensorsensing the varying strength of the magnets in the rotating drivecoupling to thereby increase accuracy in calculating the rotationalposition of the drive coupling 150.

Another aspect of the invention relates to an enhanced method of useusing a probe working end with an electrode, such as the working end 112of FIGS. 1 and 3B. As described above, a positioning algorithm is usedto stop rotation of the electrode 155 in the default centerline positionof FIG. 3B. An additional “slight oscillation” algorithm is used toactivate the motor drive 105 contemporaneous with RF current to theelectrode 155, particularly an RF cutting waveform for tissues ablation.The slight oscillation thus provides for a form of oscillating RFablation. The slight oscillation algorithm rotates the electrode 155 inone direction to a predetermined degree of rotation, which thecontroller algorithms determine from the Hall position signals. Then,the algorithm reverses direction of the motor drive to rotate in theopposite direction until Hall position signals indicate that thepredetermined degree of rotation was achieved in the opposite directionaway from the electrode's default centerline position. The predetermineddegree of angular motion can be any suitable rotation that is suitablefor dimensions of the outer sleeve window, and in one variation is from1° to 30° in each direction away from the centerline default position.More often, the predetermined degree of angular motion is from 5° to 15°in each direction away from the centerline default. The slightoscillation algorithm can use any suitable PID controlled motor shaftspeed, and in one variation the motor shaft speed is from 50 RPM to5,000 RPM, and more often from 100 RPM to 1,000 RPM. Stated another way,the frequency of oscillation can be from 20 Hz to 2,000 Hz and typicallybetween 40 Hz and 400 Hz.

While the above description of the slight oscillation algorithm isprovided with reference to electrode 155 on a rotating cutting member145 of FIG. 3B, it should be appreciated that a reciprocating electrode212 as shown in the working end 200C of FIG. 6 end could also beactuated with slight oscillation. In other words, the hook shapeelectrode 212 of FIG. 6 could be provided with a frequency ofoscillation ranging from 20 Hz to 2,000 Hz and typically between 40 Hzand 400 Hz.

FIGS. 9A-9B are longitudinal sectional views of a probe hub 120′ thatcorresponds to the working end 200B of FIG. 5 which has a reciprocatingelectrode 210. In FIGS. 9A-9B, the hand piece 104 and Hall affectsensors 240 and 245 are of course the same as described above as thereis no change in the hand piece 104 for different types of probes. Theprobe hub 120′ of FIGS. 9A-9B is very similar to the hub 120 of FIGS.2A-2B with the first and second identification/orientation magnets 250 aand 250 b being the same. The third and fourth rotation al positionmagnets 255 a and 255 b also are the same and are carried by drivecoupling 150′. The probe hub 120′ of FIGS. 9A-9B only differs in thatthe drive coupling 150 rotates with a cam mechanism operatively coupledto inner sleeve 142′ to convert rotational motion to linear motion toreciprocate the electrode 210 in working end 200B of FIG. 5. A similarhub for converting rotational motion to linear motion is provided forthe working ends 200C and 200D of FIGS. 6 and 7, respectively, whicheach have a reciprocating component (212, 218) in its working end.

Now turning to FIGS. 10A-10B and 11, the working end 400 of anothervariation of the arthroscopic shaver is shown which is similar to thatof FIGS. 1, 3A-3B and 4 which includes an inner sleeve 405 that carriesa distal ceramic cutting body or cutter 410 adapted for rotation at highspeeds in an axial bore 408 in a windowed metal outer sleeve 412. FIG.10A shows the outer sleeve 412 in a rotational position in which theouter sleeve window 415 in a first side 416 of outer sleeve 412 isfacing upwardly with teeth 418 along the edges of the window 415. Theinner sleeve 405 and the ceramic cutter 410 are rotated to a positionwherein a window 420 in the cutter 410 is facing downward and is notexposed in window 415 of the outer sleeve 412. FIG. 10B shows the entireworking end 400 rotated 180° to a position wherein a second side 422 ofthe outer sleeve is facing upwardly. As described in previousembodiments, the rotating ceramic cutter 410 can be stopped in theposition shown in both FIGS. 10A and 10B by a stop algorithm to therebyexpose the active electrode 425 carried by the ceramic cutter 410aligned generally with the centerline 428 of window 415 in the outersleeve 412 as can be seen best in FIG. 10A. With the electrode 425 inthe position shown in FIGS. 10A-10B, the physician can energize theactive electrode 425 in connection with return electrode 430, whichconsists of a portion of outer sleeve 412 and ablate or coagulate tissueby translating the electrode 425 over a targeted tissue surface.

When using the electrode 425 to delivery energy to tissue, it can beeasily understood that the saline distention fluid in the vicinity ofenergized electrode is heated by the energy delivery. It has been foundthat it is desirable to provide for a controlled fluid outflow throughthe working end 400 when the windows 415 and 420 of the respective outersleeve 412 and inner sleeve or ceramic cutter 410 are not aligned as inFIGS. 10A-10B. Such a continuous fluid flow provided by the negativepressure source 435 will then extract heated distention fluid from theworking space which can be important. Thus, as can be seen in FIG. 10B,at least one outflow aperture or flow aperture 440 is provided in thesecond side 422 of the outer sleeve 412. In a variation, referring toFIG. 10B, a plurality of elongated, narrow slots 442 are provided forsuch a fluid outflow.

FIG. 11 is a longitudinal sectional view of the working end 400 of FIG.10B and shows the fluid flow through the slots 422 into central channel444 of the ceramic cutter 410. In this variation, the slots are narrowand have a length that approximates that of window 420 in the ceramiccutter 410 through which the fluid flows into the central channel 444and extraction channel 445 that extends through the probe (see FIG. 11).The width W of the slots 442 can range from 0.005″ to 0.10″ and thenumber of slots can range from 1 to 10 or more (FIG. 10B). It has beenfound that narrow slots are preferable over larger openings to allowsuch fluid outflows as the narrow slots prevent tissue debris fromentering the slots. The total area of the slots for such outflows can beconfigured to provide a continuous flow in the range of 25 mL/min to 200mL/min. In another variation, a plurality of round or oval aperturescould be used instead of the elongated slots, wherein each such aperturehas a cross-section ranging from 0.005″ to 0.10″. In another aspect ofthe invention, referring to FIG. 11, it can be seen that thecross-section of the outflow pathway increases from central channel 444in the ceramic cutter 410 to the larger extraction channel 445 in theinner sleeve 405 which communicates with the negative pressure source.Such an increase in cross section of the fluid outflow pathway in theproximal direction assists in preventing clogs as any extracted tissueor bone chips are more effectively floating and entrained in the fluidoutflow.

Now turning to FIGS. 12A-12B, the working end 455 of another variationof the arthroscopic shaver is shown which is similar to that of FIGS.10A-10B. The ceramic cutting body or cutter 460 that rotates in themetal outer sleeve 462. FIG. 11A shows the ceramic cutter in arotational position in which the window 465 in a first side 466 of thecutter 460 is aligned with the window 470 in the outer sleeve 462. FIG.11B shows the ceramic cutter 460 rotated 180° to a position wherein asecond side 472 of the ceramic cutter 460 is exposed in the window 470of the outer sleeve 462. As described previously, the ceramic cutter 460can be stopped in the position shown in FIG. 11B by the controller'sstop algorithm to thereby expose an active electrode 475. The physicianthen can energize the active electrode 475 to ablate or coagulatetissue. In this variation, the second side 472 of the ceramic cutter 460is configured with at least one elongated slot 480 which are configuredto allow fluid flow through the slots 480. Thus, this configurationprovides fluid flows through the working end 455 to cool a distentionfluid in the working space similar to that of the working end of FIGS.10A-10B, except the slots or slots 480 are in the ceramic cutter 460instead of the outer sleeve.

In general, a resecting probe for operating in a fluid-filled workingspace is provided which comprises a shaft assembly including (i) anouter sleeve having an outer window in a distal first surface and a flowaperture in a second surface that is opposed to the first surface; and(ii) an inner sleeve with a inner cutting window rotationally disposedin a bore of the outer sleeve, an aspiration source coupled to a lumenin the inner sleeve adapted to draw tissue into the outer and innerwindows when said windows are at least partially rotationally aligned, amotor drive for rotating the inner sleeve and a controller configuredfor stopping rotation of the inner sleeve in a stop position in whichsaid outer and inner windows are not rotationally aligned, and anelectrode carried by a distal end of the inner sleeve configured fordelivering energy to tissue when the inner sleeve is in said stopposition. Such a tissue resecting probe further includes a controllerthat is adapted to operate in a first mode in which (i) the aspirationsource draws fluid and tissue into said windows when at least partiallyaligned, and (ii) the motor drive rotates the inner sleeve to resecttissue. Further, such a tissue resecting probe has a controller adaptedto operate in a second mode in which (i) the aspiration source drawsfluid through the flow aperture and inner window in said stop position,and (ii) the electrode is activated to apply energy to tissue.

A method corresponding to the invention comprises providing a probe withan elongated shaft assembly including (i) an outer sleeve having anouter window in a distal first surface and a flow aperture in a secondsurface that is opposed to the first surface, and (ii) an inner sleevewith an inner window rotationally disposed in a bore of the outersleeve, rotating the inner sleeve to thereby resect tissue whileactuating an aspiration source coupled to a lumen in the inner sleeve,stopping the inner sleeve in a stop position in which said outer andinner windows are not rotationally aligned and activating an electrodecarried by the inner sleeve to treat tissue while actuating theaspiration source to draws fluid through the flow aperture to therebycool the probe.

In this method, a controller operates in a first mode to (i) control amotor drive to rotate the inner sleeve and (ii) actuate the aspirationsource. Thereafter, the controller operates in a second mode to (i) stopthe inner sleeve in the stop position, (ii) actuate the aspirationsource, and (iii) energize the electrode to ablate or cauterize tissue.

Now turning back to FIG. 11, another aspect of the invention relating tothe working end 400 and ceramic cutter 410 is shown. As previouslydescribed, the inner sleeve 405 and ceramic cutter 410 are adapted torotate in bore 408 of the outer sleeve 412. The distal region of theceramic cutter 410 includes burr edges 490 which are configured forcutting bone. For such bone cutting, the motor drive is adapted torotate the ceramic cutter 410 at very high speeds, for example from10,000 to 20,000 RPM. As can be seen in FIG. 11, the inner sleeve 405 iselectrically conductive and functions to carry RF current from RF source485 to the active electrode 425 by electrical lead 494 indicatedschematically in FIG. 11. As described previously, still referring toFIG. 11, the outer sleeve 412 functions as a return electrode 430. Forthis reason, the inner sleeve 405 is covered with an insulator layer 495which can be an insulative heat shrink polymer, for example, FEP, PTFEor the like. The inner sleeve assembly which includes inner sleeve 405and ceramic cutter 410 as shown in FIG. 11 includes several featuresthat insure durability and electrosurgical functionality. In one aspect,the insulator layer 495 is adapted to cover the distal end 498 of theinner sleeve 405 and overlap a portion 502 of the ceramic cutter 410.Such an overlap is at least 0.10″ and preferably greater than 0.20″ andis important to insure that there is no possibility of electricalshorting between the inner sleeve 405 and outer sleeve 412 which areimmersed in a saline environment. In a second aspect, the ceramic cutter410 has a body surface 505 with an outer diameter that is dimensionedfor a snug rotating fit in bore 408 of the outer sleeve 412. Further, itcan be seen that a gap indicated at G is provided between the outersurface 515 of the insulator layer 495 and the bore 408 of outer sleeve412. It can be understood that under high rotational speeds, it isnecessary to insure that the outer surface 515 of insulator 495 does notcontact the outer sleeve 412 which would cause immediate wear on thepolymer insulator layer 495. Thus, the only bearing surface of the innersleeve assembly comprises the outer body surface 505 of the ceramiccutter 410 which rotates in the bore 408 of outer sleeve 412. The gap Gis at least 0.005″ and often greater than 0.010″.

In another aspect of the invention, as can be seen in FIGS. 10A and 11,the proximal faces 516 of the burr edges 490 closely interface with thedistal end 518 of the outer sleeve 412. The inner sleeve assembly (innersleeve 405 and ceramic cutter 410) are coupled to a proximal hubassembly (not shown) which is configured to maintain the ceramic cutter410 in an axial position without tolerance between the proximal faces516 of burr edges 490 and the distal end 518 of outer sleeve 412. In avariation, the gap indicated GG is less than 0.005″ or less than 0.002″(FIG. 11). Such tight tolerances prevents unwanted stress on both theceramic cutter 410 and outer sleeve 412 when the physician may applysubstantial sideways pressure on the working end 400 and ceramic member410 when cutting bone.

In another aspect of the invention shown in FIGS. 10A and 12B, theelectrodes 425 and 475 are configured with a plurality of sharp edges532 that allow for more effective RF current flow from the electrode totissue. In another aspect, the electrode 425 has a substantial surfacearea, and in a variation, the electrode has a surface area of at least 5mm² or at least 10 mm².

FIG. 13 shows another probe working end 545 that illustrates anotheraspect of the invention. In FIG. 13, the ceramic cutter 550 carrieselectrode 555 which is similar to the electrodes shown in FIGS. 10A and12B, except the electrode 555 includes an additional feature whichcomprises a radial edge 558 that extends outwardly from the flat surface560 of the electrode 555. The radial edge 558 extends upward to theheight of the burr edge 565. As can be understood from FIG. 13, when theceramic cutter 550 rotates in the direction of arrow AA, the burr edges565 will cut bone. When the cutter 550 is rotated in this direction(arrow AA), the radial edge 558 of electrode 555 will be on the trailingedge of the burr and will not interfere with bone cutting. However, whenthe physician actuates the controller to operate the motor drive torotate the ceramic cutter 555 in the direction of arrow BB, the radialedge 558 of electrode 555 will engage tissue as it rotates since theedge extends radially outward from the flat surface 560 the electrode555. While the active electrode 555 has been described previously beingused in a stationary position to ablate or coagulate tissue, it has beenfound that it is also useful to rotate the energized electrode 525 indirection BB. When rotating the energized electrode 555, the radial edge558 of electrode 555 can then simultaneously cut and ablate or coagulatetissue. In other words, the radial edge 558 of the electrode 555 thenuses both mechanical and electrosurgical energy to remove and ablate orcoagulate tissue contemporaneously.

Referring back to FIG. 11, it can be seen that the electrode 425 issecured to the ceramic cutter 410 by a rivet 572 shown in phantom view.FIG. 11 further shows micropores 575 in the electrode 425 thatcommunicate with passageway 576 in the ceramic cutter 410 which in turncommunicates with the interior channel 444 in the cutter 410 andnegative pressure source 435 which can reduce bubbles around theelectrode surface when using the energized electrode 425.

Now turning to FIG. 14, another variation of an arthroscopic probe isshown that is similar to that of FIGS. 3A-3B in which the RF probeworking end 600 again includes a windowed outer sleeve 605 and arotatable inner sleeve 610 (see FIGS. 15A-15B) that carries a ceramiccutting member 620 that rotates in the window 622 of the outer sleeve.In this variation, outer sleeve 605 is shown be fabricated of a metalsuch as stainless steel, however, the outer sleeve 605 and distal endthereof could also be a ceramic. As can be seen in FIG. 14, the distalend portion 628 of outer sleeve 605 includes side apertures or flowapertures 640A and 640B adjacent the window 622 that perform functionsas described previously, including cooling the fluid in the workingspace and cooling the handpiece with continuous fluid flow through theextraction channel.

It should be appreciated that a number of such side apertures in thisvariation can number from 2 to 20 or more and are spaced apart fromwindow edges 642 such that when the inner sleeve 610 is in thewindow-closed or non-aligned position as shown in FIG. 14, the apertures640A and 640B communicate fully with the interior passageway 644 withinceramic cutting member 620 and inner sleeve 610 such that aspirationfrom a negative pressure or aspiration source 220 (FIG. 1) will pullsaline through the apertures 640A and 640B.

As described previously, the inner sleeve 610 can be stopped in theposition shown in FIG. 14 with the electrode 650 fully exposed in window622. Thereafter the electrode 650 can be energized and used for ablatingor coagulating tissue. In such a method of use, the energized electrode650 can heat the saline solution in a working space which isundesirable. In this variation, an opening or aperture 655 adjacent andbeneath the electrode 650 is adapted to provide fluid outflowstherethrough. However, the volume of fluid aspirated through aperture655 is limited. In such a method of use, the fluid outflow passesthrough the passageway 644 in the inner sleeve 610 and also the flowchannel 224 in hand piece 104 (see FIG. 1). After a period of continuoususe, the energized electrode 650 can cause unwanted heating of thehandle 104 due to an extended period of time in which such heated fluidflows through the probe shaft and handle 104 (FIG. 2).

In the variation shown in FIG. 16, the negative pressure source 220(FIG. 1) can aspirate substantially larger volumes of fluid through theapertures 640A and 640B which is advantageous for multiple reasons. Inone aspect, the flows through the side apertures 640A, 640B can reduceoutflows through the aperture 655 which then reduces the chance of fluidflow through aperture 655 from extinguishing plasma that is ignitedabout the electrode 650 in a tissue ablation mode. In a second aspect,increased fluid outflows through the side or cooling apertures 640A,640B can substantially reduce the temperature of fluid in the workingspace of the joint due to increased fluid inflows into and through theworking space. In a third aspect, the continuous outflow through theside apertures 640A, 640B allows the controller algorithm tocontinuously modulate inflows to match the outflows thus maintainingexpansion of the joint cavity. In other words, the continuous inflowsand outflows prevent collapse of the joint cavity which often occurswith commercially available probes which start and stop the inflow andoutflow pumps based on pressure calculations which result in lag inresponse time. In a fourth aspect, it has been found that thetemperature of handpiece 104 (FIG. 1) can be cooled significantly, forexample, by 10° C. or more when energizing the electrode 650continuously for one minute, which is a reasonable standard forcomparing handle temperatures with a previous embodiments without theside apertures. In one variation, the fluid outflow through the sideapertures 640A-640B is at least 25 ml/min, at least 50 ml/min, at least100 ml/min, at least 150 ml/min or at least 200 ml/min. In contrast, thefluid outflow through the aperture 655 adjacent the electrode 650 isbetween 5 ml/min and 100 ml/min and more typically between 10 ml/min and50 ml/min.

FIG. 16 shows the outer sleeve 605 FIG. 14 with the inner sleeve 610 andcutting ceramic cutting member 620 removed where it can be seen that theaxial length AX of the apertures 640A and 640B is similar to, or atleast 80% of, the axial length AX′ of the electrode 650. Further, theinner edges 662 a and 662 b of the apertures 640A and 640B are sharpwhich provides additional functionality (FIG. 16). It can be understoodthat tissue debris or soft tissue may be suctioned into the sideapertures 640A, 640B when the negative pressure source 220 is operatingand the ceramic cutter 620 is being rotated to cut tissue. In suchcases, the scissor-like action between cutting edges 670 of the ceramiccutter 620 (FIGS. 15A and 15B) and sharp edges 662 a, 662 b will cut anytissue drawn into the apertures 640A and 640B. Similarly, if the probeis being used to coagulate or ablate tissue with the electrode 650 in astationary position as shown in FIG. 14, then any tissue debris adheredto electrode 650 will be cut upon rotation of the ceramic cutting member620 against the inner edges 662 a and 662 b of the side apertures 640Aand 640B.

FIG. 17 is view of another outer sleeve similar to that of FIG. 16having differently shaped side apertures 640A′ and 640B′ with sharpinner edges 680.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

Other variations are within the spirit of the present invention. Thus,while the invention is susceptible to various modifications andalternative constructions, certain illustrated embodiments thereof areshown in the drawings and have been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific form or forms disclosed, but on the contrary,the intention is to cover all modifications, alternative constructions,and equivalents falling within the spirit and scope of the invention, asdefined in the appended claims.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening. Recitation of rangesof values herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate embodiments of the invention and does not pose a limitationon the scope of the invention unless otherwise claimed. No language inthe specification should be construed as indicating any non-claimedelement as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

1.-20. (canceled)
 21. A resecting probe, comprising: an outer sleevewith an open distal end and an axial bore that extends proximally fromthe open distal end through the outer sleeve, the outer sleeve includingan outer cutting window in a side of the outer sleeve proximate the opendistal end of the outer sleeve; and an inner sleeve rotatably receivedin the axial bore of the outer sleeve so that the inner sleeve canachieve at least a first rotational position and a second rotationalposition in the outer sleeve, the inner sleeve including an axialextraction channel that extends through the inner sleeve for connectingto a negative pressure source; a rotatable drive coupling fixed to aproximal portion of the inner sleeve and couplable to a motor shaft forrotating the inner sleeve in the outer sleeve; a ceramic cutting memberdisposed at a distal end of the inner sleeve for rotation with the innersleeve, the ceramic cutting member including at least a first burrcutting edge formed therein, the ceramic cutting member also includingan inner cutting window formed therein in a first side of the ceramiccutting member, wherein the ceramic cutting member being disposed at thedistal end of the inner sleeve includes the inner cutting windowcommunicating with the axial extraction channel in the inner sleeve; andan electrode carried on the ceramic cutting member on a second side ofthe ceramic cutting member opposite the first side, wherein, with theinner sleeve rotatably received in the axial bore of the outer sleeveand with the ceramic cutting member disposed at the distal end of theinner sleeve, part of the ceramic cutting member extends through theopen distal end of the outer sleeve to position a proximal end of thefirst burr cutting edge and a proximal end of the electrode distally ofthe open distal end of the outer sleeve, wherein, in the firstrotational position, the inner cutting window aligns sufficiently withthe outer cutting window to allow fluid outflow to pass through theouter cutting window and into the axial extraction channel through theinner cutting window, and wherein, in the second rotational position,the electrode aligns with a longitudinal centerline of the outer cuttingwindow.
 22. The resecting probe of claim 21, wherein the ceramic cuttingmember includes at least a second burr cutting edge formed therein. 23.The resecting probe of claim 22, wherein the electrode is disposedcircumferentially between the first burr cutting edge and the secondburr cutting edge on the ceramic cutting member.
 24. The resecting probeof claim 21, wherein a gap of less than 0.005 inches is maintainedbetween the proximal end of the first burr cutting edge and the opendistal end of the outer sleeve.
 25. The resecting probe of claim 21,wherein a single opening in the outer sleeve provides the outer cuttingwindow and the open distal end.
 26. The resecting probe of claim 21,wherein a distal end of the inner cutting window is positionedproximally of the open distal end of the outer sleeve.
 27. The resectingprobe of claim 21, wherein a distal end of the inner cutting window islocated proximally of the proximal end of the first burr cutting edge.28. The resecting probe of claim 21, wherein the ceramic cutting memberincludes at least a first open slot formed therein in the second side ofthe ceramic cutting member proximal of the electrode.
 29. The resectingprobe of claim 21, wherein the inner sleeve includes an aspirationaperture therein that is adjacent the electrode.
 30. The resecting probeof claim 21 in combination with a handpiece coupled to the resectingprobe, the handpiece including a motor drive coupled to the rotatabledrive coupling.
 31. The resecting probe of claim 30 in combination witha controller coupled to the handpiece for controlling rotation of themotor drive and thereby controlling rotation of the inner sleeve in theouter sleeve.
 32. The resecting probe of claim 31 in combination of anegative pressure source connected to the axial extraction channel. 33.The resecting probe of claim 32, wherein the outer sleeve furtherincludes at least one flow aperture in a side wall of the outer sleeveand spaced apart from the outer cutting window.
 34. The resecting probeof claim 33, wherein the at least one flow aperture comprises at leastone elongated slot.
 35. The resecting probe of claim 33, wherein thenegative pressure source is controllable by the controller to draw fluidoutflow through the at least one flow aperture and into the axialextraction channel in the inner sleeve when the inner sleeve is in thesecond rotational position.
 36. The resecting probe of claim 35, whereinthe negative pressure source is configured to draw fluid outflow throughthe at least one flow aperture at a rate of at least 25 ml/min.
 37. Theresecting probe of claim 35, wherein, in the first rotational position,the at least one flow aperture in the wall of the outer sleeve isblocked by a wall of the inner sleeve to inhibit passage of fluidoutflow through the at least one flow aperture, and wherein, in thesecond rotational position, the at least one flow aperture in the wallof the outer sleeve is no longer blocked by the wall of the inner sleeveso that fluid outflow can pass through the at least one flow apertureand into the axial extraction channel in the inner sleeve.
 38. Theresecting probe of claim 37, wherein the inner sleeve includes anaspiration aperture therein that is adjacent the electrode.
 39. Theresecting probe of claim 38, wherein the aspiration aperture is open tothe axial extraction channel so that, when the inner sleeve is in thesecond rotational position, the negative pressure source cansimultaneously draw fluid outflow into the axial extraction channelthrough the aspiration aperture in the inner sleeve and through the atleast one flow aperture in the outer sleeve.
 40. The resecting probe ofclaim 39, wherein, when the inner sleeve is in the second rotationalposition, the negative pressure source is able to simultaneously drawfluid outflow through the aspiration aperture in the inner sleeve at arate of between 10 ml/min and 50 ml/min and through the at least oneflow aperture in the outer sleeve at a rate of at least 50 ml/min.